The document defines key terms related to computer networks and data communication. It discusses different network topologies including mesh, star, bus, and ring. It also describes different types of data transmission such as simplex, half-duplex, and full-duplex. Additionally, it defines common network architectures like LANs, MANs, and WANs as well as network components including clients, servers, protocols, and network layers.

1. Presented by
ANKIT SHUKLA
MCA

2. 1.NETWORK: A network is any collection of independent computers
that communicate with one another over a shared network medium.
2.INTERNET: The Internet is a system of linked networks that are
worldwide in scope and facilitate data communication services such as
remote login, file transfer, electronic mail, the World Wide Web and
news groups.
3.DATACOMMUNICATION: Data communication is the exchange of
data between two devices via some from of transmission medium. (such
as a wire cable).
4.MESSAGE: The message is the information(data) to be
communicated. It can consist of text, numbers, pictures, sound, etc.
6.MEDIUM: The transmission medium is the physical path by which a
message travels from sender to receiver.

3. 7.PROTOCOL: A protocol is a set of rules that govern data
communication. It represents an agreement between the communicating
devices.
8.LINK: A link is the physical communication pathway that transfers
data from one device to another.
9.TOPOLOGY: The term topology refers to the way a network is laid
out, either physically or logically.
10.MESH: In a mesh topology , every device has a dedicated point-to-
point link to every other device.
11.STAR: In a star topology, each device has a dedicated point-to-point
link only to a central controller, usually called a hub.
12.BUS: A bus topology, on the other hand, is multipoint. One long cable
acts as a backbone to link all the devices in the network.

4. 13.RING: In a ring topology, each device has a dedicated point-to-
point line configuration only with the two devices on either side of it.
14.INTERNETWORKS: When two or more networks are connected,
they become an internetwork.
15.SIMPLEX: Simplex transmission means the data flows in one
direction only.
16.HALF-DUPLEX: This transmission means allows data to flow in
both direction, but not at the same time.
17.FULL-DUPLEX: This transmission allows data to flow in both
direction at the same time.

5. LAN: A LAN is a data communication system within a building, plant,
or campus, or between nearby buildings.
MAN: A MAN is a data communication system covering an area the
size of a town or city.
WAN: A WAN is a data communication system spanning states,
countries, or the whole world.
CLIENT: A client is a finite program running on the local machine
requesting service from a server.
SERVER: A server is a infinite program running on the remote
machine providing service to the clients.

6. DNS: Domain Name System is a client-server application that
identifies each host on the internet with a unique user-friendly name.
TELNET: Telnet is a client-server application that allows a user to log
on the remote machine, giving the user access to the remote system.
FTP: File Transfer Protocol is a TCP/IP client-server application for
copying files from on host to another.
SMTP: The TCP/IP protocol that supports e-mails on the internet is
called Simple Mail Transfer Protocol.
MIME: Multipurpose Internet Mail Extension is an extension of SMTP
the allows the transfer of multimedia messages.

7. HTTP: Hypertext Transfer Protocol is the main protocol used to access
data on the World Wide Web(WWW).
NOISE: Noise is the external energy that corrupts a signal.
MULTIPLEXING: Multiplexing is the set of techniques that allows
the simultaneous transmission of multiple signals across a single data
link.
PATH: The word path refers to the physical link.
CHANNEL: The word channel refers to a portion of a path that carries
a transmission between a given pair of devices. One path can have
many(n) channels.

8. SINGLE-BIT ERROR: The term single-bit error means that only bit
of a given data unit is changed form 1 to 0 or from 0 to 1.
BURST ERROR: The term Burst error means that two or more bits in
the data unit have changed from 1 to 0 or form 0 to 1.
CHECKSUM: Checksum is used by the higher-layer
protocols(TCP/IP) for error detection.
ERROR CONTROL: Error control means error detection and
correction.
SLIDING WINDOW: Sliding window method of flow control, several
frames can be in transit at a time.

9. PROTOCOL: Protocol refers to a set of rules for executing a
particular task.
DATA LINK PROTOCOL: A data link protocol is a set of
specifications used to implement the data link layer.
BACKBONE: The major transmission path in a network.
BASEBAND: Referring to a technology in which a signal is
transmitted directly onto a channel without modulating a carrier.
BROADBAND: Referring to a technology in which a signal shares the
bandwidth of a medium.

10. BANDWIDTH: It measures the information –carrying capacity of a
line or a network.
BAUD RATE: The number of signal elements transmitted per second.
A signal element consists of one or more bits.
IP: The IP packet, called the datagram, consists of a variable header
and a variable data field.
INTERNET ADDRESS: An internet address(better known as the IP
address) uniquely defines the connection of host to its network.
ARP: The Address Resolution Protocol(ARP) finds the physical
address of a device if its IP address is known.

11. RARP: The Reverse Address Resolution Protocol(RARP) will find a
host’s IP address from its physical address.
ICMP: The Internet Control Message Protocol(ICMP) handles control
and error messages in the IP layer.
UDP: UDP is unreliable and connectionless. UDP communication is
port-to-port. The UDP packet is called a user datagram.
TCP: TCP is reliable and connection-oriented. TCP communication is
also port-to-port. The packet is called a segment.
PROTCOL PORT: is a source or destination point of an executing
program in the application layer.

12. HUB: A central device in a star topology that provides a common
connection among the nodes.
HOSTID: The part of an IP address that identifies a host.
GATEWAY: A device used to connect two separate networks that use
different communication protocols.
FLOW CONTROL: A technique to control the rate of flow of
frames(packets or messages).
FRAME: A group of bits representing a block of data.
FLOODING: Saturation of a network with a message.

13. DOMAIN NAME SYSTEM (DNS): A TCP/IP application service
that converts user-friendly names to IP address.
DATA LINK LAYER: The second layer of the OSI model. It is
responsible for node-to-node delivery.
DATA TRANSFER: The movement of data from one location to
another.
ENCODING: Transforming information into signal.
ENCRYPTION: Converting a message into an unintelligible form that
is unreadable unless decrypted.

14. DECODONG: Process of restoring an encoded message to its pre-
encoded form.
DECRYPTION: Recovery of the original message from the encrypted
data.
DIALOG: The exchange between two communicating devices.
DISTORTION: Any change in a signal due to noise, attenuation, or
other influences.
DOWNLINK: transmission from a satellite to an earth station.
DOWNLOADING: Retrieving a file or data from a remote site.

15. ERROR: Mistake in data transmission.
FREQUENCY: The number of cycles per second of a periodic signal.
HANDSHAKING: A process to establish or terminate a connection.
LINE CONFIGURATION: The relationship between communication
devices and their pathway.
LINK: The physical communication pathway that transfers data from
one device to another.
LOGICALADDRESS: The address defined in the network layer.

16. LOSS CONTROL: A transport layer function that ensures that all data
units of a transmission arrive at the destination.
LOSSLESS DATA COMPRESSION: Data compression in which no
data are lost.
LOSSY DATA COMPRESSION: Data compression in which some
original data are lost.
MICROWAVE: Electromagnetic waves ranging form 2 GHz to 40
GHz.
NODE: An addressable communication device(e.g., a computer or
router) in a network.